Solve for $x$ and $y$ using substitution. ${-3x-y = 1}$ ${y = -5x-5}$
Explanation: Since $y$ has already been solved for, substitute $-5x-5$ for $y$ in the first equation. ${-3x - }{(-5x-5)}{= 1}$ Simplify and solve for $x$ $-3x+5x + 5 = 1$ $2x+5 = 1$ $2x+5{-5} = 1{-5}$ $2x = -4$ $\dfrac{2x}{{2}} = \dfrac{-4}{{2}}$ ${x = -2}$ Now that you know ${x = -2}$ , plug it back into $\thinspace {y = -5x-5}\thinspace$ to find $y$ ${y = -5}{(-2)}{ - 5}$ $y = 10 - 5$ $y = 5$ You can also plug ${x = -2}$ into $\thinspace {-3x-y = 1}\thinspace$ and get the same answer for $y$ : ${-3}{(-2)}{ - y = 1}$ ${y = 5}$